Room-temperature fluorination of layered rare-earth hydroxide nanosheets leading to fluoride nanocrystals and elucidation of down-/up-conversion photoluminescence

Room temperature fluorination with NH4F of few-layer-thick LREH-NO3− nanosheets (~ 4 nm, RE = Y/Eu or Y/Yb/Er) has led to various fluoride compounds with phase structure and particle/crystallite morphology dependent on RE/R molar ratio. Down-/Up-conversion luminescence of the materials were investigated and deciphered in detail.126